xref: /openbmc/linux/fs/btrfs/locking.h (revision 6d99a79c)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Copyright (C) 2008 Oracle.  All rights reserved.
4  */
5 
6 #ifndef BTRFS_LOCKING_H
7 #define BTRFS_LOCKING_H
8 
9 #define BTRFS_WRITE_LOCK 1
10 #define BTRFS_READ_LOCK 2
11 #define BTRFS_WRITE_LOCK_BLOCKING 3
12 #define BTRFS_READ_LOCK_BLOCKING 4
13 
14 void btrfs_tree_lock(struct extent_buffer *eb);
15 void btrfs_tree_unlock(struct extent_buffer *eb);
16 
17 void btrfs_tree_read_lock(struct extent_buffer *eb);
18 void btrfs_tree_read_unlock(struct extent_buffer *eb);
19 void btrfs_tree_read_unlock_blocking(struct extent_buffer *eb);
20 void btrfs_set_lock_blocking_rw(struct extent_buffer *eb, int rw);
21 void btrfs_clear_lock_blocking_rw(struct extent_buffer *eb, int rw);
22 void btrfs_assert_tree_locked(struct extent_buffer *eb);
23 int btrfs_try_tree_read_lock(struct extent_buffer *eb);
24 int btrfs_try_tree_write_lock(struct extent_buffer *eb);
25 int btrfs_tree_read_lock_atomic(struct extent_buffer *eb);
26 
27 
28 static inline void btrfs_tree_unlock_rw(struct extent_buffer *eb, int rw)
29 {
30 	if (rw == BTRFS_WRITE_LOCK || rw == BTRFS_WRITE_LOCK_BLOCKING)
31 		btrfs_tree_unlock(eb);
32 	else if (rw == BTRFS_READ_LOCK_BLOCKING)
33 		btrfs_tree_read_unlock_blocking(eb);
34 	else if (rw == BTRFS_READ_LOCK)
35 		btrfs_tree_read_unlock(eb);
36 	else
37 		BUG();
38 }
39 
40 static inline void btrfs_set_lock_blocking(struct extent_buffer *eb)
41 {
42 	btrfs_set_lock_blocking_rw(eb, BTRFS_WRITE_LOCK);
43 }
44 
45 static inline void btrfs_clear_lock_blocking(struct extent_buffer *eb)
46 {
47 	btrfs_clear_lock_blocking_rw(eb, BTRFS_WRITE_LOCK_BLOCKING);
48 }
49 #endif
50